Hercules graphics in user-space

[Andy Pfiffer]

I'm trying to map the display memory on a Hercules monochrome graphics
card under Intel System V/386 into user-space.  I have not been successful.

I recently ported the Hercules driver for Microport, but setting and clearing
pixels with a system call is far too slow. 

When using the ioctl KDMAPDISP, I get EPERM.

I'd really appreciate a pointer to where to RTFM, code fragments, or anything
else that might help.  Is it true that on other versions of System V that a
shared memory segment that points at the display memory is created?  I'd really
like to know the trick to do that on Intel System V...

Thanks.

Andy Pfiffer